CBSE > Class 10 > Science | CBSE Board | Homework Help

S chand se chapter padho....chap k beech beech m jo questions hh un sab ko solve krne ki koshish kro....then ncret se chap padho aur ncert k question answer padho....okk

0Thank You

ANSWER

What will you observe when:- a) red litmus paper is introduced into solution of sodium sulphate. B) methyl orange is added to hcl. C) blue litmus is introduced into a solution of ferric chloride.

Posted by ? ... 6 years, 3 months ago

CBSE > Class 10 > Science

3 answers

Aadya Singh ? 6 years, 3 months ago

*orange

3Thank You

Aadya Singh ? 6 years, 3 months ago

a) Red litmus changes into blue. b) Methyl organge gives red colour in hcl. c) Blue litmus changes into red.

2Thank You

Yogita Ingle 6 years, 3 months ago

(1) When red litmus is introduced in solution of sodium sulfate, the color changes to blue in red litmus paper because sodium sulfate is a base.

(2) When methyl orange is added to dil. HCl, the color changes to red with methyl orange because HCl is an acid.

(3) When blue litmus is introduced in the solution of ferric chloride, the color changes to red in blue litmus paper because ferric chloride is acidic in nature.

2Thank You

ANSWER

Explain why carbon from covalent bond? Given two reasons for carbon forming a large number of carbon. Explain the formation of ammoniya molecule.

Posted by Om Yadav 6 years, 3 months ago

CBSE > Class 10 > Science

1 answers

Yogita Ingle 6 years, 3 months ago

Carbon has 4 electrons in its outermost shell and requires 4 more electrons to attain a noble gas electronic configuration. It cannot form an ion, as a huge amount of energy is required for the removal of 4 valence electrons. The ion thus formed will have 6 protons and 2 electrons, which will make it highly unstable. Carbon cannot form an ion, as its nucleus with 6 protons cannot hold 10 electrons due to interelectronic repulsion. So, carbon achieves a noble gas electronic configuration only by sharing its 4 valence electrons with other elements. Thus, it forms compounds mainly by covalent bonds.
The two main reasons for carbon forming a large number of compounds are as follows:
(a) Catenation: It is the ability of carbon to form bonds with other carbon atoms; this results in compounds having long branched chains and rings.
(b) Tetravalency: Carbon has 4 valence electrons, so it is capable of forming covalent bonds with 4 other atoms.
The small atomic size of carbon enables it’s nucleus to strongly hold on to the shared pair of electrons. Hence, carbon forms strong bonds with most other elements.

	Reaction with Oxygen	Metal + Oxygen→Metal oxide 4Na(s) + O₂(g) →2Na₂O(s) 4Al(s) + 3O₂(g) →2Al₂O₃ Metals form basic oxides Zn and Al form amphoteric oxides (they show the properties of both acidic and basic oxides) Most of the metal oxides are insoluble in water Some of them dissolve to form Alkali Na₂O(s) + H₂O(l) →2NaOH(aq)	Non-metal + Oxygen →Non-metal oxide C + O₂ →CO₂ S + O₂ →SO₂ Non-metals form acidic oxides CO and HO₂O are neutral oxides(they are neither acidic nor basic in nature) Non- metal oxides are soluble in water They dissolve in water to form acids SO₂ + H₂O →H₂SO₃
2	Reaction with water	Metals react with water to form metal oxides or metal hydroxide and H2 gas is released. 2Na(s) + 2H₂O(l) →2NaOH + H₂(g) + heat	Non-metals do not react with water, steam to evolve hydrogen gas. Because Non-metals cannot give electrons to hydrogen in water so that it can be released as H₂ gas.
3	Reaction with dilute Acids	Metal + Acid →Metal salt + Hydrogen HCl Mg(s) + 2HCl(aq)→ MgCl₂(aq) + H₂(g) H₂SO₄ 2Na(s) + H₂SO₂→ Na₂SO₄(aq) +H₂(g) HNO₃ Metal + HNO₃→ H₂ gas is not displaced. Reason- HNO₃ is strong oxidizing agent.	Non-metals do not react with acids to release H₂ gas Reason- Non-metals cannot loose electrons and give it to Hydrogen ions of acids so that the gas is released. Mn + 2HNO₃→ Mn(NO₃)₂ + H₂ H₂ gas from HNO₃
4	Reaction with salt solutions	When metals react with salt solution, more reactive metal will displace a less reactive metal from its salt solution. CuSO₄(aq) + n(s)→ ZnSO₄(aq) + Cu(s)	When non-metals react with salt solution, more reactive non-metal will displace a less reactive non-metal from its salt solution. 2NaBr(aq) + Cl₂(g)→ 2NaCl(aq) + Br₂(aq)
5	Reaction with Chlorine	Metal + Chlorine→ Metal Chloride ionic bond is formed. Therefore Ionic compound is obtained. 2Na+ Cl₂ → 2NaCl	Non-metal + Chlorine→Non-metal Chloride covalent bond is formed. Therefore covalent compound is obtained. H₂(g) + Cl₂ → 2HCl
6	Reaction with Hydrogen	Metals react with hydrogen to form metal hydride This reaction takes place only for most reactive metals. 2Na(s)+ H₂(g) → 2NaH(s)	Non-metals react with hydrogen to form hydrides H₂(g) + S(l) → H₂S(g)

myCBSEguide

myCBSEguide

Test Generator

CUET Mock Tests

Download myCBSEguide App

All Courses

Other Websites

CBSE Courses

Resources

Corporate

NCERT Solutions

CBSE Sample Papers